This invention relates to an apparatus for the equipment to a tape recorder and more particularly, to an apparatus provided with three functions: automatically detect tape thickness, measure the entire length of the tape, and determine the instantaneous position of the tape between a supply reel and a take-up reel in a tape recorder.
Cassette tapes can be classified according to the thickness into three kinds, i.e. 18.mu., 12.mu., and 9.mu., and according to the entire length of the tape into five kinds, i.e. C-30, C-46, C-60, C-90 and C-120. Tapes for open reels to be employed in a reel-to-reel type tape recorder can be classified according to the thickness into three kinds, i.e. 50.mu., 35.mu.and 25.mu.. It would be convenient if an apparatus is provided in the tape recorder, which automatically detects the tape thickness and the entire length of the tape.
A tape counter has been conventionally employed in a tape recorder for knowing the instantaneous position of the tape between a supply reel and a take-up reel. It is, however, impossible to known accurately tape position by the conventional counter, because such a counter is operated mechanically.